Treatment for a bradycardic rhythm really depends on the whether or not there are serious
signs and symptoms.
In our scenario, you’re the ACLS team leader for a 78 year female patient.
The patient is pale and diaphoretic.
She tells you that she feels dizzy and week.
She states that she started feeling this way about 3 hours ago and it’s been getting
worse.
Now because the patient is conscious and alert we can pretty much say that she’s stable
at the moment.
But since we do not have any immediate life threatening conditions, the first step is
going to be getting a set of vitals.
So you direct your assistant to check the vitals and they tell you that the patient
has respirations of around 20, heart rate of 48 and irregular, and blood pressure comes
in at 78 over 40, with an spO2 or pulse ox of 94% on room air.
Based on vitals of you would not need oxygen right away, but the the patient is obviously
bradycardic and hypotensive.
In order to know if the hypotension and bradycardia is related to a heart arrhythmia or other
cause, we should really get an ECG reading.
An assistant attaches the ECG monitor so we can take a quick look at the rhythm.
As we look at the monitor we see narrow QRS’s.
And we see a regular P-wave until the QRS is dropped.
We recognize this rhythm as, you guessed it, 2nd degree type II heart block.
But because this type of heart block is below the bundle of HIS, it can turn into complete
heart block fairly quick.
The hypotension and bradycardia is a concern so we direct our assistant to start an IV
so we can consider giving atropine.
If the patient was unstable, such as being unconscious or pulseless, you would start
with transcutaneous pacing.
But since our patient is responsive, we choose atropine first.
You direct the assistant to give .5mg of atropine rapid IV push.
The assistant repeats the order and gives the medication.
After about 1 minute we recheck the vitals, and find the respirations at 20, heart rate
still 46 and irregular and weak, and the blood pressure has not improved, it’s still 76
over 40, with the pulse ox still reading 94%.
Now based on the vitals, it looks like the atropine was ineffective.
The assistant tells you that the heart rate and the blood pressure both went down, and
the patient just became unconscious.
Now we have an unstable bradycardia.
We need to start transcutaneous pacing right away.
We direct the assistant to apply the pacing pads and turn the pacer on.
Protocols will dictate and vary from place to place, however, the American Heart guidelines
recommend that we start at 60 beats per minute.
And as the pacer is running, we turn up the milliamps until the heart muscle is captured.
In our scenario we have consistent capture at 70 milliamps.
When we have that consistent capture, we’re going to then turn the interval that our machine
has, up, so that we should turn it up the 2-5 milliamps.
Just a little bit more to keep the capture.
In our scenario we turn the milliamps up to 75.
Once you have consistent capture at 60 beats per minute, you can turn up the rate until
symptoms improve.
This is typically between 60-70 beats per minute.
In our scenario we turned the rate up to 68 and then we began to see that the patient
became responsive again.
Upon checking the vitals we now have respiratory rate of 16, a heart rate of 68 under capture
with a transcutaneous pacemaker, and a blood pressure of 96 over 60, with a pulse ox up
to 96%.
Once the patient’s perfusion has improved, we need to continue to monitor the patient.
We need to work on improving perfusion by trying to determine the cause of the bradycardia
and treating accordingly.
Now keep in mind, transcutaneous pacing can be uncomfortable, so pain management may be
something to consider, while deciding to move them to the next step for cardiac treatment.